<?php

namespace DJMixHosting;

class DownloadMix
{
    private Database $db;
    private Mix $mix;
    private bool $ready = false;
    private string $name;
    private string $djs;
    private string $filename;
    private string $url;
    private int $mix_id;
    private $content;
    private int $filesize = 0;
    private string $ext;


    public function __construct($mix, $db)
    {
        $this->db = $db;
        $this->mix = $mix;
        $this->mix_id = $mix->getId();
        $this->preDownload();
    }

    private function preDownload(): void
    {
        $this->name = $this->mix->getName();
        $buildDJs = $this->mix->getDJs();
        $this->url = $this->mix->getUrl();
        $this->djs = '';
        $djCount = 0;
        foreach ($buildDJs as $dj) {
            if ($djCount > 0) {
                $this->djs .= ', ';
            }
            $this->djs .= $dj->getName();
            $djCount++;
        }

    }

    public function download(): void
    {
        $this->loadDownload();
        if (!$this->ready) {
            echo "I had a problem downloading the file.";
            return;
        } else {
            if ($this->checkForMixDownloadCount()) {
                $this->incrementMixDownloadCount();
            } else {
                $this->addMixDownloadCount();
            }
            header("Content-Description: File Transfer");
            header("Content-Type: application/octet-stream");
            header("Content-Length: " . $this->filesize);
            header("Content-Disposition: attachment; filename=\"" . $this->filename . "\"");
            echo $this->content;
        }
    }

    private function loadDownload(): void
    {
        $this->content = file_get_contents($this->url);
        $this->filesize = strlen($this->content);
        $this->ext = pathinfo(basename($this->url), PATHINFO_EXTENSION);
        $this->filename = $this->djs . ' - ' . $this->name . ' (Downloaded from UtahsDJs.com).' . $this->ext;
        if ($this->filesize > 0) {
            $this->ready = true;
        }
    }

    private function checkForMixDownloadCount(): bool
    {
        $stmt = $this->db->prepare("SELECT * FROM mix_meta WHERE attribute = 'downloads' and mix_id = ?");
        $stmt->bind_param('i', $this->mix_id);
        $stmt->execute();
        $result = $stmt->get_result();
        $row = $result->fetch_assoc();
        $stmt->close();
        if ($row) {
            return true;
        } else {
            return false;
        }
    }

    private function incrementMixDownloadCount(): void
    {
        $stmt = $this->db->prepare("UPDATE mix_meta SET value = value + 1 WHERE attribute = 'downloads' and mix_id = ?");
        $stmt->bind_param('i', $this->mix_id);
        $stmt->execute();
        $stmt->close();
    }

    private function addMixDownloadCount(): void
    {
        $stmt = $this->db->prepare("INSERT INTO mix_meta (mix_id, attribute, value) VALUES (?, 'downloads', 1)");
        $stmt->bind_param('i', $this->mix_id);
        $stmt->execute();
        $stmt->close();
    }

    public function getExt(): string
    {
        return $this->ext;
    }

}